Drill bits

Sat Oct 05, 2013 3:10 pm

Two questions....What is the best drill bit to use when boring large holes ...I graduate up on my drill press but when I get to 5/8 or above, I'm lucky to get 3 or 4 holes in 3/8 or 1/2 inch steel...Use plenty of oil also...And what is the verdict on a Drill Doctor...Do they work...Tried step drills today...Seem to be worthless (course they were from harbor freight...) Thanks Dave

Re: Drill bits

Sat Oct 05, 2013 3:41 pm

Don't know about drill sharpeners but I do know that the larger diameter drill you use, the slower the drill bit has to turn. Once you get over 1/2", most home drill presses run the spindle way to fast and will quickly burn up the bit. You should be able to find a drill speed chart on-line easy enough. The hard part will be finding a drill press that will operate on 120 or 240 volts that will run slow enough to give you the spindle speed you need. Most that I'm aware of are single phase 480 volt units. It might be possible to step the speed down with a different pulley arrangement.

Step drills are great for thin metals, sheet metal and the like but don't well on thicker material.

What size holes are you wanting to drill?

Re: Drill bits

Sat Oct 05, 2013 3:59 pm

I'm glad Dave brought up this subject. I get frustrated with how much the big bits cost and how they don't last. I had made the (wrong) assumption that my drill press, being set at its lowest speed, was not the problem. Thanks to Ricky Racer now I know differently.

Re: Drill bits

Sat Oct 05, 2013 6:42 pm

Search for "Drill Doctor". Previously discussed.

Edit. High speed steel drill bits. Buy quality.

Larger drill bits can usually be purchased at auctions for a few dollars for a box full. Bargain considering that buying one large bit can cost $20- or more.

Nother edit: Titanium drill bits , waste of money.

Re: Drill bits

Sat Oct 05, 2013 7:04 pm

I agree to what has been said, and do like the Drill Dr., but it gets pricey when you get one big enough for the larger bits.

Re: Drill bits

Sat Oct 05, 2013 9:49 pm

I found this comprehensive list online. Back when I was young we did not have a drill press - we used a MONSTER drill that was gear drive reduced for the big drills - we still have it in the Magic Barn somewhere - I know it turned very, very slow for big drills.

Ken

Last edited by PVF1799 on Sun Oct 06, 2013 4:23 pm, edited 1 time in total.

Re: Drill bits

Sun Oct 06, 2013 5:51 am

ricky racer wrote:Don't know about drill sharpeners but I do know that the larger diameter drill you use, the slower the drill bit has to turn. Once you get over 1/2", most home drill presses run the spindle way to fast and will quickly burn up the bit. You should be able to find a drill speed chart on-line easy enough. The hard part will be finding a drill press that will operate on 120 or 240 volts that will run slow enough to give you the spindle speed you need. Most that I'm aware of are single phase 480 volt units. It might be possible to step the speed down with a different pulley arrangement.

Step drills are great for thin metals, sheet metal and the like but don't well on thicker material.

What size holes are you wanting to drill?

Rick,at the moment 5/8 and 3/4 ...3/8inch steel plate...I have a TSC drill press, not sure of the model but it was in the 200 dollar range....Has quite a few pulley arrangements...Funny I drilled holes for my splitting stands and 2 stands of the 3 drilled fine...The third set I had problems with after 4 holes and put in a new drill bit ( same manufacturer)....still had problem...I was thinking the steel may have been of different stock and harder than the previous...( I had the welding shop cut it to size for me so I don't know if they got it from the same piece or not)....Anyhow thanks, I am thinking it is exactly as you said with heat being the biggest problem...I'll look up a chart....

Re: Drill bits

Sun Oct 06, 2013 6:01 am

PVF1799 wrote:I found this comprehensive list online. Back when I was young we did not have a drill press - we used a MONSTER drill that was gear drive reduced for the big drills - we still have it in the Magic Barn somewhere - I know it turned damn slow for big drills.

Ken

Thanks Kenbrandt, I have been using bullet type....It doesn't even list them for over 1/2 inch....I'll find some twist bits...Good info thanks ( yeh, my Dad had an old Sears 1/2 inch (new to him ) that you could count the lines on the chuck as it rotated....But God forbid you hung it up )

Re: Drill bits

Sun Oct 06, 2013 6:09 am

Eugene wrote:Nother edit: Titanium drill bits , waste of money.

Bob Perry wrote: I get frustrated with how much the big bits cost and how they don't last.

John *.?-!.* cub owner wrote:I agree to what has been said, and do like the Drill Dr., but it gets pricey when you get one big enough for the larger bits.

Thanks guys, learned a lot here today... Dave

Re: Drill bits

Sun Oct 06, 2013 11:35 am

To chime in on what's already been said in my opion you get what you pay for I do not buy bits made anywhere but the US I found some at a local builders supply made by Irwin that work real well I have most of the orginal set from Sears that I have had for many years made in the US but like most everyone now they are made in china with a little practice you can sharpen these bits easily I use a belt sander and make sure the cutting edge of the bit is higher than the back side of the cutting edge.

Jim

Re: Drill bits

Sun Oct 06, 2013 1:30 pm

I have Drill Doctor with an adaptor to go to 3/4" it works very well . It was recommended to me by a mechanic .Berlin

Re: Drill bits

Sun Oct 06, 2013 1:56 pm

I have the drill doctor that goes up to 1/2 ". Love it. I'm on my second wheel. Tons of bits sharpened on the first one and could still be used. Money well spent. I have many different brands of bits but The Greenfield top them all. Not cheap but I've saved money in the long run. Grump

As a side note, the hardest steel I've worked with is old time bed rails

Re: Drill bits

Sun Oct 06, 2013 6:15 pm

I have a wide variety of drill bits for all kinds of applications .. most collected during my years as a contractor/casework supplier. Most of those bits are high end and very expensive. It pays to buy the best you can afford or the ones you need to pay your bills. Now that I am retired, I still want good quality but being on a bit of a budget -- frugality is also part of the mix, but HSS is the minimum for twist drills. I have a lot of carbides as well but those are for non-metal applications. I always keep an eye out for deals at flea markets/garage sales etc., but far more often than not I simply go to Dana and get the bits I need there. After 27 years, he still gives me contractor and better pricing so I gets to save and I gets high end bits.

Dana has also offered to do all my sharpening now that I am slightly less capable. Depth perception is a bear lately ... but I think I am going to look at a Drill Doctor 750X. That will sharpen just about all of my twist drill bits.

I have some very old Irwin Auger Bits, some that my Gramps had and some that his father had. I liked the Irwin bits until they have shipped all of the production to China. I haven't bought many of the new ones that are made off shore so the jury remains out on that one. Princess sells a lot of Irwin. They used to handle Hansen for taps and dies -- but I think Irwin bought them out too.

One of my favourite brands for hole saws, STI taps and other specialty bits is Morse.

grumpy wrote:As a side note, the hardest steel I've worked with is old time bed rails

You got that right. That stuff is hard

Re: Drill bits

I own the 3/4" Drill Doctor. Currently listed on the internet for $140- US.

Immediately after purchasing I sharpened all of my drill sets, and a bunch of dull and broken individual bits stored in various locations. Thinking the Drill Doctor easily paid for is self. Currently only sharpening individual bits, as needed.

Re: Drill bits

Sun Oct 06, 2013 9:05 pm

Eugene:

Reason I am thinking the larger one is that I have a bunch of bits that are larger than 1/2" .. figure at the price of those bits, the unit will pay for itself easily. Same price on the Cdn site.